Shrinkproofing wool with polyesters



SKPROOFDJG W901. WITH POLYESTERS Robert E. Whitfield and Lowell A. Miller, Walnut Creek,

and William L. Wasley, Berkeley, Calif., assignors to the United States of America as represented by the Department of Agriculture No Drawing. Filed Apr. 7, 1961, Ser. No. 101,599

17 Claims. (Cl. 8-128) (Granted under Title 35, U.S. Code (1952), see. 266) A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

A principal object of this invention is the provision of new methods for shrinkproofing wool. Another object of the invention is the provision of the novel products so produced. Further objects and advantages of the invention will be obvious from the following description wherein parts and percentages are by weight unless otherwise specified.

In the prior art it is suggested that the shrinkage properties of wool can be improved by applying to the wool fibers a high molecular weight polyamide such as polyhexamethylene adipamide or similar polyamide of the nylon type. This is accomplished in the following manner: The selected polyamide is first converted into soluble. form, for example, by forming an N-methylol derivative thereof. The N-methylol derivative is applied to the wool and the treated wool is then immersed in hydrochloric acid whereby the N-methylol polyamide is converted to the unsubstituted polyamide. A primary disadvantage of this known process is that it is cumbersome and inefiicient because it requires procurement of a pre-formed polyamide, conversion of this to a soluble form, and final reconversion to an insoluble form. Particular trouble is encountered in the last step where extended contact with acid is required to insolubilize the coating of N-methylol polyamide. Unless this acid treatment is complete, the polyamide will remain soluble and be removed from the textile when it is Washed.

In accordance with this invention, a pro-formed polymer is not used by a polyester is formed in situ on the wool fibers. the wool the complementary agents required to form the polyester, these agents-in the preferred modification of the invention-being dissolved in mutually-immiscible solvents. Thus in a typical embodiment of the invention the wool is first impregnated with an aqueous solution of a diol in salt form and then impregnated with a solution of a diacid chloride in a water immiscible solvent such as carbon tetrachloride. Generally, the solutions are applied in the order given above; however, the reverse order gives good results and it is within the ambit of the invention to apply the solutions in either sequence. By serial application of these solutions to the fabric, each fibrous element is coated with a two-phase system, for example, an inner layer of diol in water and an outer layer of diacid chloride in water-immiscible solvent. Under these conditions the diol and diacid chloride react almost instantaneously at the interface between the phases, producing in situ on the fibers a high molecular weight, resinous polyester which coats the fibers and renders them shrinkproof. The polymer formed is insoluble so that the shrinkproofing efi'ect is durable; it is retained even after repeated washings with soap and water or detergent and water formulations. A feature of the invention is that the high molecular weight resinous polyesters are formed in many cases at ordinary (room) temperature, which is in sharp contrast to the much higher temperatures required in the conventional melt condensations used in This is accomplished by serially applying to,

3,979,216 Patented Feb. 26, was

preparing such polymers. For example, in the usual preparation of polyesters by melt procedures, tempera turcs over 200 are customarily employed.

As noted above, the treatment in acordance with the invention renders the treated wool essentially shrinkproof so that garments produced from the treated wool may be laundered in conventional soap and water or detergent and water formulations with negligible shrinking or felting. Further, the treated wool or garments prepared therefrom are in the easy-care category in that after washing and tumble drying, they are quite free from wrinkles so that they require only a minor amount of pressing. An important point to be stressed is that the shrinkproofin-g eflfect is secured without damage to the hand of the fabric. That is, the treated fabric retains its normal hand so that it is useful for all the conventional applications in fabricating garments as is untreated wool. Other items to be mentioned are that the treatment does not cause any degradation of the wool so that there is no significant loss of tensile strength, abrasion resistance, re: siliency, elasticity, etc. Moreover, since the polymer is formed in situ on the fibersin contrast to systems where-. in polymers are spread en masse over the face of a fab-. ricthere is substantially no loss of porosity of the fabric. A further item is that the treated wool may be dyed with conventional wool dyes to obtain brilliant, level dyeings.

A particular feature of the invention and one that em-. phasizes its simplicity is that no heat-curing step is required. Following application of the two solutions, the textile merely needs to be rinsed or washed. Then, afterdrying, it is ready for use or sale.

The invention is applicable to Wool in any physical form, for example, bulk fibers, slivers, rovings, yarns, felts, woven textiles, knitted textiles, or even completed garments or garment parts.

A remarkable feature of the invention is that the polymers formed on the wool fibers are not merely physical coatings; they are chemically bonded to the Wool, that is, the added polymer is grafted onto .the wool. The. mechanism by which the graft polymerization occurs 'is believed to involve a reaction of functional groups on the diacid chloride with the free amino or hydroxy groups present in the wool molecule, these reactions giving rise' to such linkages as amide or ester which chemically unite the wool with the polymer. Thus the graft polyesters can be postulated by the following idealized formulas:

In the above formulas, W represents the polypeptide chain of the wool, containing prior to the reaction, free amino (NH or free hydroxy (-OH) groups. R and R are bivalent organic radicals (representing in this case linkages. The important point from a practical and realistic view is that chemical bonding of the polyester to the wool has been demonstrated and the theoretical nature of the mechanism of bonding is not of real concern to' the invention.

It will be evident from the description herein that the invention is of great latitude and versatility and can be employedforforming onand grafting to wool fibers a wrest/artery of ''e'nden'sation polymers, panicunriy and preferably those polymers fwherein the recurring structurescontainiat least one. ester group, that is, a group of thestructure- I Z A .ll

whereiniZ is sulphur-"or oxygen.

GENERAL CONSIDERATIONS In the practice of-the invention, selection is first made ofth'appropriate complementary agents-ehereintermed Cdrnpohent A-and ComponentB -required to form the desired polymer onthe woolfibers. The interrelationship between the nature of theagents tobe used; as- ComponemsA and B *and'the type of polymer produced is explainedin detail below in connection with the various modificationsof the invention. However, it is apropos tomenti'on' at thispoint that-in general, ComponentA maybe a did or a mixture of different diols and Component B rnay be a diacidchloride or a mixture of differ ent diacidchlorides. "Since Components A and B may be selected to form any desired type of polyestergthese components may beap'tly termed as complementary organio polyester-forming-intermediates.- They may further beappropriately designated as fast-reacting or directacting beoa'use they form the resinous polyesters rapidly and directly on contact without requiring any aftertreat menta such as treatment with curing agents, oven curestetc. I

"-Having selected the desired Components A and =B, thseare-formed into sepaarte solutions for application t'othe'wo ol was treated. An essential consideration in the preferred modification of the invention is that the sol; 'iientsjused in therespective solutions'of' Component-s- A and B be substantially mutually immiscible so that a liquidiliquid 'interface" will be set up between the two solutions on the wool fibers. Thus, for example, ComponentA is dissolvedlin water and Component B is dis solved in benzene carbon tetrachloride, toluene, xylene, ethylene. dichloride, chloroform, hexane, octane, petroream ether or othervolatile' petroleum distillate, or any other inert, water-immiscible solvent. The two solutions are then-applied .to the wool-serially, that is, the'wool is treated .first with one solution, thenwith the other. The order of" applyingthe'solutions is not critical; Genorally, the solution of Component A is applied firstand the-solution of Component B is applied next; however, theireyerse order .givesgood results and it is within the ambit of the invention to apply the solutions in either sequence.

The solutions may lie'applied to the wool in any desired way as long a'sthey are applied serially. A preferred method involves immersing the wool in one solution, removing excess liquid as by use of squeeze rolls, immersing the wool in the second solution, again removing excess liquid, rinsing the "treated fabric in water and then drying it. Conventional apparatus consisting of tanks, paddingrollsfsqueeze rollsv andthe like aregenerally used in applying the respectivefsolutions. The'amount of each-solution. applied to the textile maybe. varied by altering the residence time in'the solutions, the-pressure exerted by the squeeze rolls and by varying the concentration of the active materials in the respective solutions. To decrease carry-over of the solvent from the first treating solution to the second solution, the wool after its immersion in the first solutionmay'be subjected to drying conditions such. as a current of warm air to concentrate thesolution carried by thewool.

As noted; above, a critical-factor in the preferred formof the inyentionj. is that the; complementary-agents- Component A and Component B-are serially applied to the textile dispersed in solvents which are substantially mutually immiscible. The'nature of the solvents is of no consequence as long as they are. essentially inert and' possess the above-stated property of substantial immisci- 'bility. Usually, volatile solvents are preferred as they in waterandlnay thus be .applied to the textile in aqueous solution. In such case the solvent for Component B may be any inert, essentially water-immiscible organic solvent. Typical illustrative examples thereof are benzene, toluene, xylene, carbon tetrachloride, ethylene dichloride, chloroform, hexane, octane,-,petroleum ether or otherjvolatile petroleum fraction. It is, however, not essential that Component A be employed in aqueoussolution. "I'hus, oneinay utilize a system of two essentially immiscible organic solvents, Component A being dispersed'in one solvent and Component B in'the'o ther. As 'anexample', Component A may be dispersedin 2- -brornoethyl acetate and Component B dispersed in benzene; Another example involvesusing formamide, dimethylformamide, or diethylformamide as the .solvent ror Component A and using n-hexyl ether as the solvent for Component B. 'A further example involves a.system of adiponitrile as the solvent for Component A and ethyl-ether as the solvent for Component B. Examples ofo'ther pairs'of solvents which are substantially immiscible with one another and which may 'be'used for preparing the solutions of the respective reactants are Z bro'moethyl acetate and n-hexyl ether, ethylene glycol diacetate and n-hexyl ether, adiponitrile and n-butyl ether,

adiponitrile'and 'carbontetrachlon'de, benzonitrile and formamide, n-bu-tyl ether and formarnide, di-N-propyl aniline andformamide, isoarnyl sulphide and formamide, benzene and formamide, butyl acetate and-forrnamide, benzene and nitromethane, 'n-butyl ether and 'nitro methane, carbon tetrachloride and formamide, dimethyl aniline and formamide, ethyhbenzoate and-foramide.

In cases where Component A is -a diol in' the form of its. alkali-metal salt, the solvents therefor may contain hydroxy groups. Because alcoholate and phenolate ;v groups areso'mueh more reactive than hydroxy groups, there will 'be little ifany interference by reaction of the hydroxy groups'of the'solvent with the active agents of Component B, particularly if the solutions of the reactants are at ordinary temperatures. In'such event, then, solvent pairs of the'following types may be employed: Di-

caland may be varied widely. Generally, it is preferred 'thateach of 'thepairof solutions contains aboutfrom l to 20% of the respective active components. In applying the process of the invention, enough of the respective solutions are applied to the wool to give a polymer deposit on the fibers of about 1 to'l0%. Such'amount's provide a substantial degree of shrinkproofing with no significant reduction in hand of the wool. Greater amountsof polymer may be deposited on the fibers if desired but tend to change the natural hand of the wool. Also, thicker deposits are likely to contain substantial amounts of'nongraited polymer. -The relative amounts of Component A and Component, B applied to the wool maybe varied. as desiredtor individual circumstances. Generally, it is preferred to apply the, components in equirnolar proportions, that is, the amounts are soselected thatthere are the same number functional groups provided by Component A asprovided by the functional'groups of Component B.

It is often desirable to add reaction promoters or catalysts to either of the solutions of Components A or B in order to enhance reaction between the active agents. For example, in cases where the system involves reaction between a diol and a diacid chloride it is desirable to add to either of the solutions, preferably the solution of Component A, a sufficient amount of alkaline material to take up the HCl formed in the reaction. For such purpose one may use a tertiary amine such as pyridine, dimethyl aniline, or quinoline or an alkali-metal hydroxide, or, more preferably, an alkaline material With buffering capacity such as sodium carbonate, sodium bicarbonate, trisodium phosphate, borax, etc. The reaction of Components A and B may also be catalyzed by addition of such agents as tributyl tin chloride, stannous tartrate, ferric chloride, titanium tetrachloride, boron trifluoride-diethyl ether complex, or tin salts of fat acids such as tin laurate, myristate, etc.

Where one of the solutions of the reactants contains water as the solvent, it is often desirable to incorporate a minor proportion of a surface-active agent to aid in dispersing the reactant and to assist in penetration of the solution into the textile. For this purpose one may use such agents as sodium alkyl (C -C sulphates, the sodium alkane (C -C sulphonates, the sodium alkyl (C -C benzene sulphonates, esters of sulphosuccinic acid such as sodium dioctylsulphosuccinate, and soaps, typically sodium salts of fat acids. Emulsifying agents of the non-ionic type are suitable, for example, the reaction products of ethylene oxide With fatty acids, with polyhydric alcohols, with partial esters of fatty acids and polyhydrie alcohols or with alkyl phenols, etc. Typical of such agents are a polyoxyethylene stearate containing about 20 oxyethylene groups per mole, a polyoxyethylene ether of sorbitan monolaurate containing about 16 oxyethylene groups per mole, a distearate of polyoxyethylene ether of sorbitol containing about oxyethylene groups per mole, iso-octyl phenyl ether of polyethylene glycol, etc. Generally, only a small proportion of surface-active agent is used, on the order of 0.05 to 0.5%, based on the Weight of the solution. In addition to, or in place of, the surface-active agent, a supplementary solvent may be added to the primary solvent (water) in quantity sufiicient to disperse the active reactant. For such purpose one may employ acetone, or other inert, volatile solvent, particularly one that is at least partially miscible with water. It is evident that the solutions of Components A and B need not necessarily be true solutions; they may be colloidal solutions, emulsions, or suspensions, all these being considered as solutions for the purposes of the present invention.

Ordinarily, the treatment of the wool with the solutions of the complementary agents is carried out at room temperature (particularly where the diol is used in salt form) as at such temperature the polymerization takes place very rapidly, that is, in a manner of a minute or less. If, however, a higher rate of polymerization is desired as in continuous operation on long lengths of cloth the second solution may be kept hot, for example, at a temperature up to around 150 C. Also, where the agents used include a diol as such (in contrast to the alkali salt thereof) it is preferable to heat the second solution as the polymerization rates with the diols are generally unsatisfactory at room temperature.

As has been explained above, in the preferred modification of the invention the solutions of Components A and B-the complementary condensation polymer-forming intermediatesare serially applied to the Wool in the form of mutually-immiscible solutions to provide a liquid-liquid interface between the solutions as they are serially laid onto the fibers. In a less preferred modification of the invention, a system is used which utilizes a solid-liquid interface. Such a system is established in the following Way: The wool is first impregnated with a solution of one of the complementary agents-for example, Component A--dispersed in an inert, volatile solvent. The wool is then subjected to drying as by subjecting it to a current of hot air. The wool fibers which are now covered with a deposit of the first component in a solid state are then impregnated with the complementary agent-Component B, in this case, dispersed in an inert, preferably volatile solvent. In this way the fibers are layered with a superposed system of solid Component A and a solution of Component B. Under these conditions polymerization takes place rapidly forming the polymer in situ on the fibers and grafted thereto. In this system it is not essential that the respective solvents be immiscible. Thus, for example, Component A may be applied in water solution and Component B in a water-miscible solvent such as dioxane or acetone. A typical example of practicing this modification involves immersing the wool in an aqueous solution of a diol in salt form, removing the wool from the solution, squeezing it through rolls to remove excess liquid, subjecting it to a draft of hot air until the wool isdry to the touch (about 10-20% moisture in the impregnated Wool) and then immersing the wool in a solution of a diacid chloride dissolved in an inert, volatile solvent. The wool is then removed from this second bath, squeezed through rollers to remove excess water, rinsed, and dried in air. Although this system is operative, it is not a preferred technique because the polymerization at the solidliquid interface is slower and less uniform in degree ofpolymerization and the degree of shrinkproofing afforded to the wool per unit weight of polymer formed on the fibers is less than with the system of mutually-immiscible solutions.

COMPONENTS A AND B As noted briefly above, the selection of Components A and B depends on the type of polymer desired to be formed on the wool fiber and grafted thereto. Typical examples of compounds which can be employed as Comgolnent A in a practice of the invention are described e ow.

As the diol one may employ any of the aliphatic, aromatic, or heterocyclic compounds containing two hydroxy groups, preferably separated by at least two carbon atoms. The diols may be substituted if desired with various noninterfering (non-functional) substituents such as ether groups, sulphone groups, tertiary amine groups, thioether groups, fluorine atoms, etc. Typical compounds which may be used are listed below merely by way of illustration and not limitation: Ethylene glycol, diethylene glycol, 2,2-dimethyl propane-1,3-diol, propane-1,3-diol, butane-1,4-diol, hexane-1,6-diol, octane-1,8-diol, decane- 1,10-diol, dodecane-l,l2-diol, butane-1,2-diol, hexane-1,2- diol, l-0-rnethyl glycerol, Z-O-methyl glycerol, cyclohexane-1,4-diol, hydroquinone, resorcinol, catechol, bis(para hydroxyphenyl) methane, l,2-bis(parahydroxyphenyl) ethane, 2,2-bis(parahydroxyphenyl) propane, 2,2-bis(parahydroxyphenyl) butane, 4,4'-dihydroxybenzophenone, naphthalene-1,5-diol, biphenyl-4,4'-diol, 2,2-bis(3-methyl- 4-hydroxyphenyl) propane, 2,2-bis(3-isopropyl-4-hydroxy phenyl) propane, 2,2-bis(4-hydroxy-dibromophenyl) propane, etc.

If desired, mixtures of difierent diols may be used. It is also within the purview of the invention, though less preferred, to use the compounds containing more than two hydroxy groups as for example, glycerol, diglycerol, hexanetriol, pentaerythritol, etc. Moreover, it is Within the spirit of the invention to utilize the sulphur analogues of the diols. Thus, for example, instead of using the compounds containing two hydroxy groups one can use the analogues containing either (a) two SH groups or (b) one Sl-I group and one OH group.

Among the preferred compounds are the aliphatic diols, for example, those of the type:

scrapie wherein n has a value from '2 to 12. Another preferred category ofaliphatic Compounds are the polyethylene glyols, i.'e.:

HO'CH CH CH I CHg] "O-f-CH CH OH wherein nihasa value from zero to A preferred catcgoryof'aromatic diols are the bi'sphenols, that is,'compounds of the type r R! 7 RI wherein -R-C-'-'-R'represents an aliphatic hydrocarbon group containing l 012133113011 atoms and R represents hydrogen or a lower alkyl radical. In'this category especially preferred compounds are 2,2'-bis(parahydroxyphenyl) propane, often-designated as bisphenol-A; 2,2-bis ('3-methyl-4-hydroxyphenyl) propane; 2,2-bis(3-isopr.opyl- 4-hydroxyphenyl) propane; and brominated derivatives of bisphenol A, such as 2,2 bis( l-hydroxy-dibromophenyl) propane.

The-diols are employed'as such or in the form of their alkali-metalsalts, that is, as alcoholates or phenolates, depending on'whetherthe diols are aliphatic or aromatic. The alkali-metal derivatives' arepreferred asthey will react with theactiveagents of Component B at room'temperature. With the diols, as such, temperatures above room temperature-are generally required to promote reaction withtheir' complements in Component B. In such case proper temperature .for the reaction can be achieved by holding the second solution into which the textile is immersed, at about 50 to 150 C. It is obvious that the solvent selected for the 'second' solution will need to be one which has a boiling point above the temperature s'electe'd, or,in the alternative, a pressurized system can be usedto maintain the solvent in the liquid phase.

i Inthe modification of the invention wherein water is used as thesolvent for Component A (a diol in this case) and Component B is dispersed in a water-immiscible, inert solvent, it is preferred to use aromatic diols in their salt (phenola'te) form. This affords several distinct advantages. Thus the alkali-metal phenolates are quite soluble iii-water, they are relatively stable in aqueous solution (in contras'tto'the alcoholates), and they will react at room temperature with diacid chlorides so that no heating is required. 7

Typical examples of compounds which can be employed as Component B in a practice of the invention are described below.

As the diacid chloride one 'may employ any of the aliphatic, aromatic, or heterocyclic compounds containing two ca'rbonylchloride (-COC1) groups, preferably separated by at least two carbon atoms. The diacid chlorides may be substituted if desired with non-interfering (nonfunctional) substituents such as ether groups, thioether group'sgsulphone groups, etc. Typical examples of compounds in this category are listed below merely by way o fillustration and notlimitation: Oxalyl chloride, maleyl chloride, furnaryl chloride, malonyl chloride, succinyl chloride, glutaryl chloride, adipyl chloride, pimelyl chloride, suberyl chloride, azelayl chloride, sebacyl-chloride, eyclohexane-l,4 biscarbonyl chloride, phthalyl chloride, isophthalyl chloride, terephthalyl chloride, 4,4'-biphenyldicarbonyl chloride, fl-hydromucon'yl chloride, i.e.,

diglycolic acid chloride, i.e., O-(CHr-COCD higher homologues of this compound as 0(CH -CH -COCl) dithiodiglycollic acid chloride, diphenylolpropanediacetic acid chloride, i.e., (CH C(C' H OCH COCD and the like. If desired, mixtures of different diacid chlorides may nausea. It is also evident that the sulphur analogues of these compounds may be used and are included within the spirit of the invention. Thus, instead of using compounds containing two -#COCl' groups one may use com- 8 pounds containing one -CSCl and one -COCl group or compounds containing two -CSC1 groups. Moreover, although the diacidchlorides are preferred asthey are reactive and relatively inexpensive, the corresponding bromides and iodides maybe used.

As the diacid chloride, it is generally preferred to use the aliphatic compounds containing two carbonylchloride groups in alpha, omega positions, particularly those of the type:

ClCO(CH COCl wherein n has a value from 2 to 12; Another preferred category includes the compounds of the formula (where A is the benzene or cyclohexane radical), especially para-substituted compounds such as terephthalyland hexahydrote'rephthalyl chlorides.

Numerous variations in the basic procedure herein described will suggest themselves to those skilled in the art in the application of the invention without departing from the fundamentals of the invention. Some of these variations are explained below.

If desired, one may prepare a prepolymer containing internal ester units and terminalhydroxy groups. Such prepolymers can be prepared, for example, in known manner by reacting a molar excess of diol with a diacid chloride. The prepolymer could then be used as Component A while for Component B one would use a diacid chloride. A typical example in this area would be to use as Component A a prepolymer of the type-- 0 o it il .HO-RO R -ooR-0H and tense as Component B a diacid chloride (ClCOR"COCl) thus to produce a polyester containing repeating units of the type- 0 o o 0 O-R -O Rl lOR-0i 3R"t I (In these formulas R, R, and R" represent bivalent organic radicals.)

In the alternative, one may prepare a prepolymer containing internal ester units and terminal carbonylchloride groups. Such ,a prepolymer used as Component B in conjunction with a diol asComponent A would yield a polyester similar to that shown above.

it is evident from the above description that there is a very wide choice available in the selection of the complem-entary agents so that generically the polyesters de posited onto the wool and grafted thereto'will' contain repeating units of the typewhere R represents a bivalent organic radical; Z represents an oxygen or sulphur-atom; and R represents a bivalent organic radical or a bond linking the two carbonyl groups. In the preferred modifications of the-invention, Z is oxygen; R and R represent bivalent hydrocarbon radicals or bivalent hydrocarbon radicals interrupted by internal ether (O-) linkages. In the especially preferred modifications of the invention, the reactants are so chosen that R and R represent bivalent hydrocarbon radicals containing at least two carbon atoms.

There has been set forth above a comprehensive disclosure of the preferred types of complementary agents, that is, diols, diacid chlorides, and their equivalents. Although it is preferred to use these agents for optimum results, they are by no means the only compounds which may-be used. The invention in its broadest aspect includes the application of many other types of complementary agents which have the ability to form polyesters when applied to wool by the disclosed procedures.

Various examples are thus set forth of other types of compounds which may be used.

Polysulphonatesformed by the conjoint use of a diol and a disulphonyl chloride: In a typical example in this area, an aqueous solution of a diol--preferably in the form of its alkali-metal salt-is first applied to the wool, followed by application of a disulphonyl chloride in inert, essentially water-immiscible solvent. For this purpose one may use any of the diols exemplified above. Typical disulphonyl chlorides which may be used are benzene- 1,3-disulphonyl chloride, biphenyl-4,4-disulphonyl chloride, toluene disulphonyl chlorides or aliphatic compounds such as those of the formulawherein n has a value from 2 to 12. A variant of this procedure is to use the corresponding dithiol in place of the diol, thus to form a polythiolsulphonate.

An alternative to the diacid chlorides is the use of mixed anhydrides of the corresponding dicarboxylic acids with monobasic acids such as trifluoroacetic acid, dibutylphosphoric acid, or the like. Such mixed anhydrides may be employed, for example, as Component B in conjunction with a diol or dithiol as Component A to form polyesters or polythiolesters, respectively.

Examples The invention is further demonstrated by the following illustrative examples.

Standard shrinkage test.-The tests for shrinkage referred to in Examples 1 to 4 were conducted in the following way: The wool samples were milled at 1700 r.p.rn. for 2 minutes at 40-42 C. in an Accelerotor with 0.5% sodium oleate solution, using a liquor-to-wool ratio of 50 to 1. After this washing operation the samples were measured to determine their area and the shrinkage was calculated from the original area. With this washing method, samples of Control (untreated) wool gave an area shrinkage of 47%. The Accelerotor is described in the American Dyestufi Reporter, vol. 45, p. 685, Sept. 10, 1956.

EXAMPLE 1 A. A solution was prepared containing 4% of the sodium salt of 2,2-bis(parahy-droxyphenyl) propane and 0.1% of a commercial wetting agent isooctylphenyl ether of polyethylene glycol) in water.

B. A solution was prepared containing 3% terephthalyl chloride in methylchloroform.

A sample of wool cloth was immersed in solution A for 60 seconds, run through squeeze rollers to remove excess liquid, immersed for 60 seconds in solution B, run through squeeze rolls to remove excess liquid, rinsed with water, and dried in air.

The treated wool had a polyester resin uptake of 1% and on washing exhibited an area shrinkage of 21.7%.

EXAMPLE 2 The procedure of Example 1 was repeated using as solution B 3% sebacyl chloride in carbon tetrachloride. Two runs were made, in one case holding the wool 30 seconds in each solution, in the other holding the wool 60 seconds in each solution. The results are tabulated below:

A sample of wool cloth was immersed for 30 seconds in a solution of 3% terephthalyl chloride in methylchloro- Polyester resin de- Area posited shrinkage, on W001, percent percent EXAMZPLE 4 (1) A sample of wool cloth was immersed for 30 sec onds in a solution of 3% sebacyl chloride in carbon tetrachloride. The cloth was run through squeeze rolls to remove excess liquid, then immersed for 30 seconds in a solution containing 5% of the potassium salt of ethylene glycol (KOCH -CH OK) in isopropyl alcohol. The cloth was run through squeeze rolls to remove excess liquid, rinsed with water, and dried in air.

(2) A sample of wool cloth was immersed for seconds in a solution containing 5% of the potassium salt of ethylene glycol in isopropyl alcohol. The cloth was run through squeeze rolls to remove excess liquid, then immersed for 120 seconds in a solution of 3% terephthalyl chloride in carbon tetrachloride. The cloth was run through squeeze rolls to remove excess liquid, rinsed with water, and dried in air.

The results are tabulated below:

amples 1 to 4 and a sample of the untreated wool were subjected to washing in a household automatic washer using a medium water level, 0.1% low-sudsing detergent, 3-pound wash load, 40 C. water temperature, and with a wash-cycle of 30 minutes. This method of washing is approximately equivalent to ten modern-fabric washes in a household automatic machine. The results of this washing on shrinkage are tabulated below.

Sample: Area shrinkage, percent Example 1 10 Example 2, run 1 6 Example 2, run 2 6 Example 3 '7 Example ,4, run 1 8 Example 4, run 2 8 Untreated control 30 This application is a continuation-in-part of our copending application Serial No. 98,718, filed March 27, 1951, entitled Shrinkproofing Wool With Polymers, wherein is disclosed the broad concept of grafting condensation poly; mers-particularly polyamidesto wool. Said application is a continuation-in-part of the following application: Serial No. 90,604, filed February 20, 1961, entitled Shrinkproofing of Wool With Polyamides (which in turn is a continuation-in-part of Ser. No. 22,651, filed April 15, 1960); Serial No. 83,848,'fi1ed January 19, 1961, entitled Shrinkproofing of Wool With polyurethanes; Serial No; 85,438, filed January 27, 1961, entitled Shrinkproofing of Wool With Polyureas; Serial No. 88,232, filed February animals "1 1 9, '1961-, entit-led Shrinkproofing of Wool withiPolyesters; and Serial No. 88,233, filed February 9, 1961, entitled Shri'nkproofing of Wool With Polycarbonates. .Of the application's referred to above, thefollowing have been abandoned: Ser. No. 22,651, so. No. 83,848, Ser..No. 85,438, Ser.-No.88,232, Ser. No. 88,233,:a1'1d'ISC1'..NO. 90,604.

Attention is called to the factfthat'the present-application is one of a series of applications :filed by. us generally concerned with shr-inkproofingwool wherein various types of condensation polymers areformed: on and grafted to the wool fibers. Polyesters are the subject of the present application; polyurethanes are the subject of Serial No. 99,- 319, filed March 29, 1961; polyureas are the subject of Serial No. l00,476,"filed April 3, 1961'; polycarbonates are the subject of Serial No. 102,323, filed April 11, 1961; interpolymers arethe subject ofSerial-No. 109,229, filed May 10, 1951. Condensationpolymers broadly and polyamides specifically are the subjects of the parent application referred to above, of which this application is a continuation-inapart.

Although the present invention fi'ndsits greatest field of utility in the shrinkproofing of wool and is peculiarly adapted for such use because of a combination of important factors-including the advantages that a high degree of shrink resistance is imparted with a minor amount of polymer, that the shrinkproofing treatment does not significantly impair the hand of the wool, that the treatment does not impair other desirable fiber characteristics such as tensile strength, elasticity, porosity, etc, that the polymer is grafted to thewool molecules so that the .shrinkproofing eifect isexceedingly durable and is retained even after long wear and repeated laundering-4t is evident that the invention may be extended to other areas. Thus the principles of the invention may; be extended to forming polymers in situ on other substrates besides wool, particularly substrates; of a fibrous structure. Typical examples of such-materials are animal hides, leather; animal hair; cotton; hemp; jute; rarnie; flax; wood; paper; synthetic cellulosic fibers such. as viscose, cellulose acetate, cellulose acetate-butyrate; casein fibers; .poiyvinyl alcohol protein fibers; alginic fibers; glass fibers; asbestos; and organic non-cellulosic fibers such aspolylethylene glycolterephthalate}, polyacrylonitrile, polyethylene, polvinylchloride, polyvinylidene chloride, etc. --'Such applications of the teachings of the invention may be for :the purposes of obtaining functional or decorative efiectssuch as sizing, finishing, increasing gloss or transparency, increasing water-repellcncy, increasing adhesionor bonding-characteristics of the substrates with rubber, polyester resins, etc. It is not claimed that in such. extensions. of our teachings shrinkproofing would be attained nor that graft polymers would be produced. However, it might be expected that graft polymers would be formed with proteinous substrates such as animal hair, animal hides, and the like.

. .Having thus described the invention, what is claime'dis':

1; A process for shrinkpr'oofing wool without significant impairment of its hand which comprises .serially impregnating wool with twdsolutions, one solution containing a diol dispersed in water,the.other solution containing a diacid chloride dispersed in an inert, volatile, essentially water-immiscible solvent, the said diol and diacid'chloride reacting to form in situ on the wool fibers a resinous polyester.

. 2. .The process of claim '1 wherein the diol has the formula HO(CH OH where n has a value from 2 to 12.

3. The process of claim 1 wherein the diol is an aromatic diol.

4. The process of claim 1 wherein the diacid-chloride has the formula ClCO(CH COCl where n has a value from 2m 12.

- 5. The process of claim 1 wherein the diacid chloride is terephthalyl chloride.

6. A process for shrink'proofing wool'without'si ificant impairment. of itshand which comprises serially impregnating wool with two solutions, one solution containing a diol in a first solvent, the other solution containing a diacid chloride in a second solvent, said first and second solvents being substantially mutually immiscible, the said diol and diacid chloride reacting to form in situ on the wool fibers a resinous polyester. 1 7. A. modified wool fiber which exhibits improved shrinkage properties as compared with the unmodified wool fiber comprising wool fiberrhaving arpolyester formed in situ-thereon and chemically bonded to the wool.

8. A modified 'woolfiber which exhibits improved shrinkage properties as compared with the unmodified wool fiber comprising wool fiber having a polyester formed in situ thereon and chemically bonded to the wool, said polyester containing recurring'structural units of the formula- 0 .O R O ii wherein R and R are bivalent organic radicals.

9. The product of claim 8 wherein R is ---.(CH wherein n has a .value of 2 to 12.

10. The product of claim 8 wherein R is a bivalent aromatic radical.

11. The product of claim 8 wherein R is (CH in which n has a value of'2 to 12.

12. The product of claim -8 wherein R is a bivalent aromatic radical.

13. A process for treating a fibrous material which comprises applying serially to said material in interfacial relationship, a pair of complementary organic polyesterforming intermediates. 1 14. A process for treating a fibrous material which comprises serially applying to said material a pair of com plementary direct-acting organic polyester-forming intermediates inseparate phases of limited mutual solubility. .15. A process. fortreating a fibrous material which comprises serially distributing on the surface of the fibrous elements-of said material a pair of complementary directacting organic polyester-forming intermediates in superposed phases of limited mutual solubility, the said intermediates reactingunder such conditions to form a polymer in situon said fibrous elements.

16. A process for treating wool which comprises distributing on the surface of the wool fibers a pair of complementary direct-acting organic polyester-forming intermediates in superposed liquid phases of limited mutual solubility, said intermediates reacting rapidly under said conditions to form a polymer in situ on said fibrous elements and grafted thereto.

17. A. process for treating a fibrous material which comprises serially impregnating a fibrous material with two solutions, one solution'containing one member of a pair of complementary direct-acting, organic, polyesterforming intermediates in a first solvent, the other solution containing the complementary member of said pair of complementary, direct-acting, organic, polyester-formingintermediates in asecond solvent, said first and second solvents being substantially mutually immiscible, the said .pair of intermediatesreacting rapidly under said conditions to form in situ on the fibers a resinous polyester.

' References Cited in the file of this patent UNITED STATES PATENTS 2,012,267 Carothers Aug. 27, 1935 2,780,608 Hurwitz et al Feb. 5, 1957 2,827,359 Kine et al. Mar. 18, 1958 2,915,419 Wolfrom Dec. 1, '1959 2,917,410 Vitalis Dec. 15, 1959 2,992,944 Binkley. July 18, 1961 2,993,748 Koenig July 25, 1961 

1. A PROCESS FOR SHRINKPROOFING WOOL WITHOUT SIGNIFICANT IMPAIRMENT OF ITS HAND WHICH COMPRISES SERIALLY IMPREGNATING WOOL WITH TWO SOLUTIONS, ONE SOLUTION CONTAINING A DIOL DISPERSED IN WATER, THE OTHER SOLUTION CONTAINING A DIACID CHLORIDE DISPERSED IN AN INERT, VOLATILE, ESSENTIALLY WATER-IMMISCIBLE SOLVENT, THE SAID DIOL AND DIACID CHLORIDE REACTING TO FORM IN SITU ON THE WOOL FIBERS A RESINOUS POLYESTER. 